Entrained air too low

[McSEpllc]

Hi Everyone,

Today the first segments of many site retaining walls were poured. The air content of the concrete of the wall was tested at 2%.

Specified are:
4,000 psi concrete,
6% air +/- 1.5%,
W/C ratio of 0.4.

The mix has 2.85 cu ft of cement,
1 cu ft of type F fly ash,
10.6 cu ft of 1” coarse aggregate, and
6.4 cu ft of fine aggregate.

The wall in question will be exposed (no veneer), it will not be exposed to de-icing salts.

I consider the particular wall location to be an exposure category F1 (moderate: exposed to freeze thawing with occasional exposure to moisture.) That would require an air entrainment per ACI of 4.5% +/-1.5%, so a low end of 3%.

Is there a surface treatment that can help?
What would you do?

Eric McDonald, PE
McDonald Structural Engineering, PLLC

 

[spats]

You could try to waterproof the surface to keep moisture from entering the wall, but it seem like you wouldn't want to do it until the concrete is well cured, and has been completely dried out.

 

[Ron]

Sealing the concrete is the only recourse other than removal and replacement with properly air entrained concrete.

 

[XR250]

What about applying a surface hardener/densifier such as W.R. Meadows Liqui-hard?
Don't know if that will work, but might be worth finding out.

 

[McSEpllc]

Thanks Everyone!
I will have the GC research and propose a surface sealant.

Eric McDonald, PE
McDonald Structural Engineering, PLLC